The Khazars were a semi-nomadic Turkic people with a confederation of Turkic-speaking tribes that in the late 6th century CE established a major commercial empire covering the southeastern section of modern European Russia, southern Ukraine, Crimea and Kazakhstan. The Caspian Sea is still called the Khazar Sea in many eastern languages. In Iranian language, Turkmen language, in Azerbaijani language, in modern Turkish and in many eastern dialects it is called Khazar Sea. The Khazars created what for its duration was the most powerful polity to emerge from the break-up of the Western Turkic Khaganate. Astride a major artery of commerce between Eastern Europe and Southwestern Asia, Khazaria became one of the foremost trading empires of the medieval world, commanding the western marches of the Silk Road and playing a key commercial role as a crossroad between China, the Middle East and Kievan Rus'. For some three centuries (c. 650 – 965) the Khazars dominated the vast area extending from the Volga-Don steppes to the eastern Crimea and the northern Caucasus.
Khazaria long served as a buffer state between the Byzantine Empire and both the nomads of the northern steppes and the Umayyad Caliphate and Abbasid Caliphate, after serving as the Byzantine Empire's proxy against the Sasanian Empire. The alliance was dropped around 900. Byzantium began to encourage the Alans to attack Khazaria and weaken its hold on Crimea and the Caucasus, while seeking to obtain an entente with the rising Rus' power to the north, which it aspired to convert to Christianity. Between 965 and 969, the Kievan Rus' ruler Sviatoslav I of Kiev and his allies conquered the capital Atil and destroyed the Khazar state as an independent one. It became the autonomous entity of Rus' and then of Khazar former provinces (Khwarazm, were Khazars were known as Turks, in the same way as Hungarians were known as Turks in Byzantium, Volga Bulgaria)
Determining the origins and nature of the Khazars is closely bound with theories of their languages, but it is a matter of intricate difficulty since no indigenous records in the Khazar language survive, and the state was polyglot and polyethnic. The native religion of the Khazars is thought to have been Tengrism, like that of the North Caucasian Huns and other Turkic peoples. The polyethnic populace of the Khazar Khaganate appears to have been a multiconfessional mosaic of pagan, Tengrist, Jewish, Christian and Muslim worshippers. A part of the Khazars joined the ancient Hungarians in the 9th century. The ruling elite of the Khazars was said by Judah Halevi and Abraham ibn Daud to have converted to Rabbinic Judaism in the 8th century, but the scope of the conversion within the Khazar Khanate remains uncertain.
Proposals of Khazar origins have been made regarding the Hungarians, the Kazakhs, the Cossacks of the Don region and of Ukraine, Bukharan Jews, the Muslim Kumyks, , the Turkic-speaking Krymchaks and their Crimean neighbours the Crimean Karaites, to the Moldavian Csángós, the Mountain Jews, even some Subbotniks on the basis of their Ukrainian and Cossack origin and others. The late 19th century saw the emergence of the theory that the core of today's Ashkenazi Jews are descended from a hypothetical Khazarian Jewish diaspora which migrated westward from modern-day Russia and Ukraine into modern-day France and Germany. Linguistic and genetic studies have not supported the theory of a Khazar connection to Ashkenazi Jewry. The theory still finds occasional support, but most scholars view it with considerable skepticism. The theory is sometimes associated with antisemitism and anti-Zionism. More details
